Israel has launched its deadliest strikes on Gaza since the United States-brokered ceasefire took effect nearly three weeks ago, saying the attacks were a direct response to what it claims are breaches of the agreement by Hamas.

More than 100 Palestinians, including 46 children, were killed late on Tuesday and into Wednesday, according to medical officials. Israeli air attacks targeted locations across the territory, flattening several residential buildings and leaving families buried beneath rubble.

By Wednesday afternoon, the Israeli army said it had "returned to the ceasefire" under political leadership directives but warned that it remained ready to strike again if required. The military reported attacking over 30 locations it described as "terrorist command positions.".\

Among the dead were at least 18 members of one extended family in central Gaza — children, parents and grandparents — highlighting the continuing civilian toll of the conflict. Rescue workers continued to search through collapsed structures in Gaza City's Zeitoun neighbourhood after what Palestinian officials said were multiple Israeli strikes.

Israel's renewed assault followed a dispute over the handling of Israeli captives. Late Tuesday, Israeli officials said a body transferred from Gaza via the International Committee of the Red Cross was not one of the 13 expected to be returned under the ceasefire terms. Forensic experts identified the remains as belonging to Ofir Tzarfati, taken captive during the Hamas-led October 7 attacks. His partial remains had previously been recovered in November 2023.

The discovery prompted fury among senior Israeli officials, particularly far-right ministers who oppose halting the war and demand Hamas's complete destruction. Families of Israeli captives also expressed outrage and called for action.

Shortly after, Hamas's Qassam Brigades said it was prepared to transfer the remains of another captive by 8pm (18:00 GMT), but the group reported it paused the process when Prime Minister Benjamin Netanyahu ordered "powerful strikes" on Gaza.

Gunfire and explosions were heard in Rafah in southern Gaza overnight. Israel said the sounds signalled a Hamas attack, a claim the group rejected.

Palestinian health authorities say at least 68,643 people have been killed and more than 170,000 wounded since Israel launched its war on Gaza in October 2023.